Steam-accumulator apparatus for steam plants



J. RUTHS ET AL STEAM ACCUMULATOR APPARATUS FOR ySTEAM PLANTS SUNW Feb'. 1.6 1926. A y A 1,572,961..

J. Ruil-Hs ET As. -4

STEAM ACCUMULAT'OR APPARATUS FOR STEAM PLANTS Filed Juiv 1o', i922 'l 5 sheets-shew e Egh- 16 192@ J. RUTHS ET AL STEAM ACCUMULATOR APPARATUS FR. STEAM PLANTS 1922 5 shexs-shee-b s Filed Jly lO Mb.. 16,1926., $1,572g96l J. RUTHsrx-:T Al.

STEAMV ACCUMULATOR APPARATUS FOR STEAM PLANTS l.

FiledJuly 1Q, 1922 f fj-sheets-Sheei 4 Feb. i6 1926. '1,572,961

' J. RUTHS ET A L STEAMl AGCUMULATOR APPARATUS FOR STEAM-PLANTS File-d July 1o, 1922l 5 sheets-sheet s Patented Feb. 16, 1926.

UNITED STATES IPATENT OFFICE.

JOHANNES `RWIHS, F LDJURSIILIVI, vAND NILS PERSSON, 0F B'REVIK, LIDINGON, SWEDEN, ASSIGNORS T0 AKTIEBOLAGET VAPORAGKUMULATOR, OF STOCKHOLM,

SWEDEN, A CORPORATION.

STEM-ACCUMULATOR APPARATUS FOR STEAM PLANTS.

Application filed' July io, 1922. serial No. 574,089.

To all ywhom. it may concern.'

Be it knownA that we, JOHANNES RUTHs and NiLs IiiiissoN, subjects of the King oi' Sweden, residing at, respectively, Djurs- D holin, Sweden, and Brevili, Lidiiigon, Sweden, have invented certain new and use ful Improvements iii Stoamccuiiuilator Apparatus for Steam Plants (for which we tiled application for patent in Sweden, May '30, 1921), ol which the following is a specification.

In steam plants equipped with accumulators it is old to cause the steani to pass through a motor such as'a turbine or a reciprocating engine iii which power is ex tracted, after which the steam is led to low pressure consumers it' all the steam can be used-therein; or, when more steam isv supplied tlian is needed by the low pressure coii`- sinners, the surplus is led from the motor to an accuii'iulator to be stored,` from which accumulator the steam is withdrawn for use when necessity demands. In such plants, the back pressure or extraction pressure ot' the motor, that is to say, that pressure to which the steam ior theV low pressure consumers expands in the motor is either alwaysl higher than the highest accumulator pressure or the same as that pressure and variable therewith. Iii the latter'cases where the extraction pressure is substantially the same as and varies with the pressure in the accumulator, it is evident that `tlieain`ount of power extracted in the motor is a function ot' the variable pressure in the accumulator.

In some instances, it has been found that itis possible to `extract more power from the steam. for the low pressure consumers if this steam can `expand iii the motor 4from the high pressure Ot the line from which it is takeiiall the way down to the pressure at which the low pressure consumers use steam and have this complete expansion irrespective oi' variation-s ot pressure in the accumulator, and the surplus of steam generated over the momentary consumption is led in a path parallel to the path of steam passing' through the motor to the accumulator, from which steam is led to the low Apressure consumers when the demand `on these consumers is greater than the supply afforded by the motor.

The present inventionhas for its purpose to provide means whereby the greater extraction of power in the motor as above outlined is accomplished and comprises an arrangement.including one or more steam generators; a steam condu'it system connectedI therewith; a steam accuii'iulator, a motor, and one or more low pressure consumers connected in said conduit system; in coinbiiiation with means to. carry out the purpose set forth, involving a conduit leading steam troni the accumulator to the low pressure. consumers, a reducing valve' or the equivalent in Athis conduit and means wherey by steam extracted from the motor is led to this conduit at a point behind the reducing valve, that is, between the reducing valve and the low pressure consumers, and also involving certain regulating` mechanisms necessary to thel best realization of the in- I veiitioii, the function and advantages of which will be apparent as the description proceeds. j v

' In the accompanying drawings which are a part of this specification:` I

Figure l is a diagram showing typical curves ot steamconsuniption and generation in a plaiitviii accordance with this invention, the curves being arranged in a special way, as will hereinafter be described.

Fig. 2 is an arrangement of a plant in accordance with the present invention and shows the manner of connecting the accumul'a`t0r and tlie'steam generator yto the low pressure line.

Fig. 3 shows a plant in accordance with 'the present invention wherein certain pressure operated regulating mechanisms ai'e used, which are more fully explained hereinafter. f

Fig. 4 is another plant having a different means of regulation. f

Fig. 5 is another plant showing still anotherform of regulation.

Fig. 6 is ai arrangement including a single extraction turbine. p Fig. 7 is an arrangement similar to Fig. G with a different form of regulation.

Fig. 8 is an arrangement using a. double extraction turbine.

F ig. 9 is a regulating' arrangement indetail.

To best. understand the invention the various elements nand characters shO-wii oii the drawings will first be explained in a general way, particular reference beinghad to Fig.

2. In the various figures of the drawings like charactersfrepresent like parts. A represents the boilers in which steam'is generated. B is a conduit connectedto the boilers for receiving steam therefrom at boiler pressure. C is a steam motor, in the illustration a non-condensing, back pressure tur- Y bine, receiving 'steam from the high pres. sure conduit B. Theturbine drives an electric generator D, delivering electric power to theielectric circuit E. K and Gr are parts of a conduit within the plant system which is at lower pressure than the main high pressure conduitB and steam generator A. The Q .conduitA K is herein termed an accumulator conduit. The pressure in this conduit varieswith variations of press-ure in the ac- .herein termedlowpressure conduit.

cumulator F. G is the conduit from which the low pressure consumers, such as paper' machines I-I are supplied with steam. -Gris n conduit K--G between accumulator conduit K and low pressure conduit Gr is provided a reducing valvel J. i

According to the present invention theA back pressure steam passes'to the low pressure conduit G at a point after the reducing valve J. By this arrangement it is possible to keep the backpressure independent e of the pressure in the accumulator F, `and equal to the pressure of the low pressure consumers, although itis lower than the pressure in the accumulator. The valve M in'conduit L opens and allows steam to pass to the accumulator .F when the pressure in the conduit B rises above a predetermined value. j

Valves operating in this manner to increase the valve opening lwhen theactuating pressure increases and to decrease the valve opening when :the pressure decreases, we

term over-flow valves.

In the conduit N, connecting conduit B with conduit K is a reducing valve .O which opens ir" the pressure which controls it should sink below a: predetermined value.

' Thisvalveoperates. to allow steam' to pass' towards the accumulator incertain cases if the accumulator is completely discharged. The small lines connecting the valves with. the steam conduits indicate'by which pressure the valves are-operated.l

In the operation of the plant according to Fig. 2, steam is generated in steam genera; tor A and passes into conduit B. Here the steam divides itself into two paths, the one through conduit L and through or past the accumulator, through` valve J, and thence to the low pressure consumers; the other path being through the supply conduit to the motor G, through the motor C, through the back pressure connection 5l and thence, also, to the low pressure consumers. Thus it is seen that there .are two parallel paths or steam leading from generatorA A to con# it is only necessary to provide the stea1n 75 motor with a speed regulator which -will come into play only if the motor for some reason or other should speed up too much.

If a uniform steam production is to be obtained and no steam losses are to occur, as 30,

is always greater than the consumption of the high pressure motor, i. e., the turbine'C, and this must be the case at any and every moment and, further, whe-re the consumption of the steam motor never exceeds the momentary generation Steam plants are seldom so simple that they can beai'ranged' in this-way. To assure a good working it is usually necessary to regulate the flow of steam to the steam motor `by two pressures,

and preferably-also by the speed of the 95,

wherein certain coiisuineis such as digesters 10" receive steam directly from the boilers or from a conduit in the system connected ahead of the motor. v A study of these curves will indicate-the mode of operation'l andthe necessity in the majority of cases for t'he pressure operated regulating mechanisms hereinbefore referred to. In this figure the ordinates represent steam quantity and the abscissas represent time.

The line a represents the average consumption of the plant which is the same as vthe amount of steam generated in the boilers. That the boilers can be made to generate this `constant average quantity of steam is due toithe fact that the accumulator takes care or all variations in steam consumption wherever they occur in the plant and the boilers are' relieved of theselvariations.

The steam consumption of the consumers connected directly with the boilers or the high pressure conduitis indicated by curve measured upwardly from the horizontal axis of. coordinates.` This might be called' the` curve of high pressure steam consumption. l

rIlhe steam consumption 'of the consumers connected to the low pressure line is laid out -in the diagram downwardly from the line a, for reasons apparent as the description proceeds, and is indicated by the line c, referl ence bein; had to the values at. the right of units.

Fig. l. This might'be called the curve ot low pressure st 2am consumption.

At a'given time (l, the amount ot steam supplied by the boilers is represented by the ordinate e; the consumption ot the high pressure consumers is represented by the ordinate f, and .the consumption of the low pressure consumers is represented by ordinate vg. The last quantity g passes through the motor. At this time, then, the tol'al steam consumption is )i plus g which is loss than the steam generation e. The di tl'ereuce between the steam generation and the steam vconsumption is indicated by linevJz which rrepresents the quantity oit cam passing` to the accumulator to be stored.

Consideration ot the diagram at this time (l, therefore, shows that the low pressure consumers need only g steam units and the high pressure consumers f steam units and there is a surplus generation ot 7L steam Since the low pressure consumers need only f/ units there must be some regulation which will prevent the la, units ot steam from passingintothe motor and thence to thelow pressure units. The surplus must be taken care of before the steam arrives at the low pressure line, since the connection leading steam to the accumulator is connected to thehigh pressure conduit and. iusueh cases, the quantity passing to the low prefisure consumers becomes the decidingV factor and it becomes evident that in this ease the abovev mentionedA regulation must be controlled by the pressure in the low pressure consumers or conduits connected therewith. In other words, in such a case where there is a greater generation than both high and low pressure consumers will take there must be a regulation which will prevent `more than the quantity g from entering' the motor and this regulation must becontrolled by the condition which controls the amount g, Anamely the condition in the low pressure conduit.

At another time z', the steam consumption ot the high pressure consumers is represented by ordinate 7c; the steam consumption ot the low pressure consumers is represented by ordinate Z, and the steam generation is, as before, equal to the value represented by line o which equals 7c plus m. At this time the total steam consumption is greater than the steam generation by an amount equal to n.. This last valuen represents the amount of steam rejected by the accumula tory at this time Consideration of the diagram at this time 2'., therefore, shows that the high pressure consumers need 7u steam units. and it this amount is supplied thereto there remains but m units to pass through the motor. However the low pressure consumers need Z units and therefore there must be a recula- `curve e the regulat-iouis chang-ed. o might be called the regulation curve Aan d o coincide.

tion which will prevent more than m units from passngto the motor so that the highv uppermost on the igure. This curve represents the controlling values g and m. lt is evident that at veach time-the Curve Z) crosses Curve Curve o measured downwardly from linea From the' above description it, will b( seen that in the plant ot Fig. l, two devices -represents the 'quantity of steam flowing"vv through the motor.

through the motor, namely when' curves o' and o coincide. This is indicated on the diagram by the letter r. The other device operates when less steam passes through the motor than is required by the low pressure consumers, namely when the curves This is indicated on the diagram by the letter a. rThe first device is to be goi'ierned by the pressure behind the motor in accordance with pressure in the conduits connected with thelow pressure 'ensuinersg the otherv by the steam pressure before the motor. These devices, operated bythetwo diiterent pressures, can be combined into vone device operated by the two pressures; as will be hereinafter explained.

As seen from the diagram, the steam quantity flowing' through the steam Amotor will lvary much less at a plant like this, than it" all the steam, not consumed directly :from the high )rossure line, should pass through the niotor as the case is in accumulator plants already known. Hence, a much hi {rher thermo-dynamic etliciency will be obtained in the steam motor.

Figs. '-lto '8 show practical plants lar.- ranged with regulating' devices governedby the two pressures 4and will bevdescribedY in order. In almost all cases it is necessary, beside the two pressure regulations above deserilj ed- 4to have a regulation responsive to the speed of the motor. In Fig. 3 the various parts are indicated with the same numerals as in Fig. 2.

The plant shown in Fig 3 is one wherein the turbine delivers power to-a circuit E in whichv all the generated powercan be used. In this case the speed regulator and the pressure regulators are all arranged before the turbine in the supply oonduit 55. `In this ligure is shown, diagrammatically, a consumer. I3, for insta-nce, agroup of digesters, connected to the highpressure con` "duit B.- Q is an over- :tlow valve responsive tothe pressurein iront ot' it and tunetioning to increase its fiow area upon increase of pressure and decreasing itsflow Vareairpon decrease of pressure. AR is a reducing valve' responsive i to the pressure in the back pressureline of the motor, op-

erating in such Aa manner 'thatiitl the pres' sure 1n the low pressure conduit drops th valve opens more or less. S is a speed regulator controlling the admission ot' steam tothe motor. As indicated by the fact that the kballs ofthe speed governor are in their lowermost position, the governor is in the nature of a safety .device and is normally inoperative, coming into play only if the speed of the 2lLmotor rises above a value somewhat higher vvice of regulating nature-at the higher speed is not like' the known emergency than the normal speed of the motor in which case the speed governor diminishes the amount of steam tlowing'to the motor and takes over the regulation from the valves Q and R; Grovernorv S, being a control de valve' which lcompletely'shutsoV the steam to a motorat high speed. This latter type of valve maybe `addedto4 the motor in addition to the regulator S.v Normally, the valve controlled by the speed. governor is wide open and the steam to the motor is` controlled by the two valves Q, and R, the. one responsive to the pressure in the high pressure conduit and the other responsive plant shown inv Rig.

is set to open ata somewhat lower pressure than the valve M and so the valve Q, at'

this time will be wide open and the valve M controls the flow of 'steam to the accumulatoi` and a ,constantpressure is main# tained in the conduit B. v i Suppose now that the steam pressure in the lowpressure conduit should drop as a result. of more steam being needed by the lowpres sure consumers. The valve R thenopens wider and lets more steam pass through 'the turbine to thelow pressure line.

'cumulatorz It the drop in pressure is so great that the pressure drops in the main conduit duo to the fact'that the'steam vconsumption has become greater than the steam generation, namely the condition at the time z' in the diagram of Fig. l, the-valve R will open wide,the valve M will close and the valve Q will throttle down to diminish the supply ot' steam to the motor. The reducing valve .l which isadjustedto open at alower presf sure in conduit G .than that atwhich the valve R opens due to the drop of pressure in the low pressure conduit which allows steam to pass from the accumulator to the low pressure conduit. In this case the valve Q, is the device lwhich controls the steam lowthrough the turbine.

Suppose under these conditions that the pressurein the low pressure conduit rises,

as when some ofthe low pressure consumers are cut out of service. The valve J then closes, the 'valve R diminishes the flow of steam through the motor, the valve Q opens Awide and the valve M vopensand regulates the passage ot the surplus generated steam over the momentary consunipton to the ac- Cil rlhis is again the condition atthe time d and the pressure behind the mo-v tor controls the How ot steam therethrough.

It, on the other hand` the variations are in conduit B the plant will operate as follows:

Suppose the pressure in conduit B rises,

las whena steam consumer connected to this drops in conduit B, as when more steam is taken to a steam consumer connected to this line. The valve M shuts, first, 1f 1t 1s open, and, afterfthat, it the pressure drops further valve Q, starts to shut, letting less steam through the turbine.

Thus the pressure drops in conduit G causing valve R to increase 'its flow area.

However, asthe steam flow in'this case lis limited by valve Q, more steamcannot be'talten to the turbine and, consequently,

the pressurein the low pressure conduitl drops more until lalve .I opens and the ac@ cumulator delivers enough st'eamto the low pressure conduit to keep its pressure at its predetermined working value.

It the accumulator should be entirely discharged reducing valve O opens letting steam pass from the high pressure conduit to the low pressure consumers.

etlect on the operation since the through the turbine 1s at this time regulat thus allowing the surplus If the speed of the motor should become excessive, as when all the power generated by the motor is not needed in the electric circuit, the speed regulator S comes into operation and regulates the flow otsteam to the motor. vIn. Figure S this regulator is shown with hanging` arms, vwhich means, that it operates only when the speed of the motor is above a fixed value somewhat higher than the' normal speed of the motor, as above mentioned.

'Another arrangement is shown in Fig. 4. ln this en'ibodinient the overliow valve Q is inserted in ,the back pressure line 5l but it is, yas before, responsive to the pressure in conduit- B. Valve R- is inserted, as in the arrangement according to Fig. 3 in the conduit beforethe turbine andis governed by the back pressure. Otherwise the plant' is similar to vthat of Fig. 3.

The operation of this plant is as follows:

Suppose the pressure in the low pressure conduit G rises. The tiow through valve R then decreases and consequently the pressure in conduit B rises. This rise ot' pressure in conduit B opens valve Q butthis has no steam tlow ed b v valve B. Consequently opening of valve Q does not lower the pressure in conduit B which rises more, opening valve M steam to pass to the accumulator; l

It the pressure 'in conduit G should decrease for some reasonyvalve R opens wider and allows more steamito pass to the turbine. In case this opening of valve R should cause `a drop of pressure in conduit B, valve Q is actuated to decrease the flow of steam thereA through thereby limiting' the steam flow to the low pressure line. This in turn causes a rise ot' pressure in the back pressure line ahead of valve Q and consequently valve R closes pressure in the turbine from rising too high. t now more steam is needed in the low pressure conduit G, valve .l opens and the accumulator delivers the steam that is needed.

lt, tor some reason, the pressure rises in conduit B, the flow through valve Q. increases 'and more steam passesto conduit G. ln case the amount thus passing to conduit G is more than is needed bythe low pressure consumers the back pressure ot` the turbine rises and consequently the flow through valve R iscorrespondingly decreased. Consequently until valve M opens enough to allow the cxcess ot' steam generated to passito thev aecun'iulator. i

It the pressure in conduit B falls the drop of pressure causes valve Q'to close somewhat. ll. as a consequence, the quantity flowing through valve Q is less than somewhat thereby preventing they example, to an increase the pressure rises in conduit B th rough valve Q what is needed by the low pressure consumers, the-deficiency will be supplied `by the accumulator through valve J. The decrease oi. tlow through valve Q causes a rise of pressure in the turbine exhaust in front oft valve Q which, in turn, causesvalve R to decrease lthe How therethrough in corresponding degree.

Fig. 5 shows a plant in which the function of reducing valve R is taken over by valve M. In this plant an over-flow valve Q is providethas before, in the conduit in front of the motor, governed by the pressure in the main conduit B and a speed regulator is provided operating as before described.

As pointed out, in connection with the diagram of Fig. l, in they majority of cases, twolregulations are necessary,one governed by the pressure in the high pressure conduit and the other by the pressure'in the low pressure conduit. The. various devices, as seen from the above disclosure govern, in ettect, the relative amounts of steam passing to the motor and to the accumulator. It is possible as shown in Fig. 5 to have the regulation governed by the pressure in the low pressure conduit act directly on the valve controlling the supply to the accumulator. In this arrangement the Over-HOW valve M is governed by the pressure in the back pressure line in such a way that the valve opens on rise of pressure actuating the same and closes on drop of this pressure.

This plant operates as follows:

Assume at a given time, a certain quantity of steam Hows through the motor and a certain quantity through conduit L. Suppose, now, the pressure in conduit B rises.

.Valve Q then opens wider due to this rise of pressure and more .steam fiows through the motor. It the consumption of the loW pressure consumers does not increase there will be a rise of pressure in conduit G. This rise ot pressure 'causes valve M to open Wider allowing the surplus of steam generated to pass to the accumulator. Increase of flow through valve M causes a drop of pressure in conduit B which causes valve Q to close somewhat and thus a new state of balance is obtained wherein a greater amount of steam passes through valve M.

the pressure in conduit B should drop, under the above assumed conditions, due, for of.consumption ir the high pressure consumers, the over-flow valve Q then is operated pressure to decrease yits creasing the How of steam'to lthe motor. If, now, less steam passesthrough theinotor vthan what -is 'needed in the low pressure consumers, the pressure in conduit G drops. This causesvalve M to shut partly or entirely. decrease of iow How opening, de-

The consequent through valve 'M causes an increase oftlow dueto changes of pressure due to the drop of' in conduit B. lf, despite the increased flow through valve Q and the motor, there is not enough steam in the low pressure conduitthe pressure therein drops still further and valve J opens, admitting steam from the accumulator thereto. y

Suppose the pressure in theL low pressure conduit G rises. Valve M is then operated to allow more steamto pass to the accumulator. Consequently the pressure in conduit B drops and this drop in pressure causes valve Q to decrease its flow opening whereby the pressure in conduit G is reduced It, on the other hand, the pressure in conduit G should drop, valve M shuts either partly or entirely and consequently the pres sure in conduit B rises causing valve Q to open, increasing the flow through the tur-- bine. If, in this operation, there is a deticiency of steam in the low pressure conduit G despite the increased iow through the motor, valve J opens .and the accumulator deliverssteam to the low pressure conduit. If theaccumulator should.y at this moment, be completely discharged valve O in conduit N opens, allowing steam to pass to thelow pressure line G. l

Figure 6 shows a plant in which an extraction turbineris provided instead of the non-condensing turbines of the previous arrangements. -The turbine consists in a high pressure section T and a low pressure section lbine could be used in the circuit.

U. The exhaust ot the low pressure section is directly connectedvto a condenser V. 'Between thetwo sections of the turbine a valve is arranged in the connection 52 controlled.

by a speed governor X to regulate the steam flow to the low pressure section of the tur- An extraction connection or bleed line 51, corresponding to the back pressure line 51 of the previous.arrangements connects the steam communication 52 betweeii-tlie two'V sections of the turbine with conduitG at a' point in the steam communication 52 ahead of the valve 50.

In-thisxcase the exact amount of power" needed in the electric circuit E will be' generated by the turbine, differing in this respect from the previous arrangements where all the power generated by the tur- I" the steam passing from the high pressure section to the low pressure section is not suffi; cient for the power demanded, steam Will 'low" from the accumulator through valve J, connection 5l, valve 50 and coinmunil cation 52, to the low pressure section. This is very im'portant wherethe Aconsumption varies greatly. Valves Q and R are similar' in construction andv function to those of Fig. 3. f

lVith the above explanation4 the operation of the plant will be easily understood by raz/aser pressure conduit G, andgoverned by apen-- -trifucal 0'overnor in normal manner. Thus the plant .fs like that of Fig. 3except for the additioh of'a speed governed /inotor supplied from conduit AG. Now just as F ig.'

4 was evolved from Fig. 3 by moving over iiow valve Q\to the back pressure connection 5l but, however, retaining its control as responsive to the pressure in conduit B,

so an arrangement may be made according toFig. 6 except-that overflow valve Q is placed in extraction connection 51 but is governed bythe pressure in conduit B. The operationwillthen be the 'same as that of: Fig. 4 except for the influence of the speed governed consumer, that is, the low pressure section of the turbine. It is to be y observed, however, that if valve"Q is placed in connection 51 at a point between its jointure with communica-tion .'52 and tie low pressure conduit Gl that the plant must be one wherein the steam consumption ot the tion of the steam boilers at any time since the low pressure section can then not take steam from the accumulator. If, howeveif the valve-Q is placed closeup to the motor before the jointure of connection. 5l with communication 52, the low vpressure section' can `take steam fronr the accumulator and thus the motor may at `times consume more steam than is generated. p

Furthermore, as the-plant according to Fig. 5 was evolved from Fig. 3 by omitting valve .R and changing the regulation of valve M so that it is responsive to the pres sure previously controlling valve R, so an arrangement can be made according to Fig.

6 except that the regu-lation of valve M is changed to responsiveness to the'pressure in connection' 51 'and valve R removed. The operat'on will then be the same as that of Fig. 5 except for the influence of thelow pressure section ofthe turbine.

As is obvious, in'practice the turbine sections would in most probability be united into one casing, 'which casing would* also include valve 50 controlling the flow of stean .to the low pressuie'yvheels.

The showing'pof the turbine and the speed regulators is obviously merely diagrammatic and may haveniany forms in prac- 4motor does'not exceed the steam productice. The speed regulation may include any mechanisn'i which will lirst regulate the steam tlow tothe low pressure section, and, when this is completely shut oli', reduce the steam flow to the high pressure section. Such mechanisms are well knownfr Fig. 7 illustrates aplant embodying an extraction turbine in wh ch the pressure operated ralres connected with motor lines are arranged in a ditterent manner than previously described.

'In this construction an over-dow valve Z is inserted in the conmninication 52. This valve Z is regulated by the extraction preslvsure in connection 5l in such a way that it increases the iiow of steam to the low pressure section it' the extraction pressure increases and decreases the flow ot' steam therethrough if the extraction pressure de creases. `Valve Q is inserted in' the extraction connection 5l between conduit G and the point at which connection 5l is connected to connection 52. Thfs valve is regulated as beforeby the pressure in conduit 'Speed regulator S regulates the iiow of steam to the high pressure section and 1s normally in operative action, as is shown vby the outward position oi. the balls of the governor. Speed regulator X is normally inactive as is shown by the drooping position of the arms ot the governor and comes speed of the turbine consequently increases and speed regulator Scuts down the flow ot steam to the highV pressure4 section.- This causes a rise ot pressure in conduit B.. rise of pressure in conduit- B causes opening ot valve Q, but this has no etl'ect as the steam flow `to the motor is determined by speed regulator S and valve Z. The result, then, of the rise'ot pressure in conduitv B is to cause Valve M to increase the amount of steam passing through conduit M to-the accumulator.

Suppose the pressure in conduit Gr decreases. The resulting; drop of pressure in conduit 5l causes valve Z todecrease its low area, decreasing' the flow ot steam to the low pressure section U. Consequentl);Y more steam passes to the'low pressure conduit'G. Assuming the load on the motor is un.- changed, ,the revolutions of the motor decrease due to the decreased flow of steam G will ris This to the low pressure section U' and speed regulator S causes more steam to pass to the high pressure section of the turbine, which section now takes `over-the load taken from the low pressure section lwhen valve Z decreased the steamv flow thereto. Thus the deficiency' in the low pressure conduit is niade up partly by cutting' oil the tiow to the low pressure section and partlyby increasing4 the flow through the high pressure section. If under these conditions the de mand for steam in the. low pressure conduit is greater than what can be supplied through the bleed connection 51, the pressure in conduit G drops further' and valve J iscauscd to open so that steam is delivered to the low pressure conduit from the accumulator conduit K.

lt the ).uessure in conduit B should drop too 'much when speed regulator S increases the flew -to the high pressure section, valve Q closes somewhat. cutting ott a corresponding quantity ot' steam vfrom the low pressure conduit. In this event, a decrease in pres- I sure in the low pressure 'conduits causes Yali'e J to open. f

Suppose the pressure vin conduit B rises for some reason. Thi.` rise in pressure causes valve Q, to increase its fiow area and more steam passes to the low pressure conduit. lf the consumption in the low pressure consumers has not increased in corre spending` degree, the pressurein the conduit As a result valve 'Z will be opened wider, permittingv more steam` to flow to the lonT pressure section. This causes an increase of the turbine speed and speed regulator S causes the flow ot' steam to the highV pressure section to be decreased which,

1n turn, causes the pressure Ain conduit l5 to increase and this-incrcase of pressure actuates valve M to open the same and allow` the surplus to flow to the accumulator i Suppose the pressure in conduit B drops. It valveM is open, it then closes partially or entirely. After valve M has closed completely valve Q, is actuated to decrease the flow ot steam-through it and less steam passes through the turbine to the low sure conduit. This causes a rise in pressure in connection 5l before the valve Q and this rise in pressure causes valve Z to increase the flow of steam to the low pressure section of the turbine. V.This increases the number of revolutions ot the turbine and consequently speed regulator Sl cuts oit' a part of the steam passing.,r to the high pressure section of the turbine. l

This causes the pressure in conduit B to rise again and the deiiciency of steam in the low pressure consumers is supplied by the accumulator F through Valve J.' It lthe accumulator should happen to be dischargf'egd,y

pres

.consumers P1 are connected.

Valve Q in communication 53 between the high and intermediate sections ofthe turbine is an overflow valve actuated by the pressure in the bleed line from the high pressure section. y

Valve .R in this same connection is a reducing valve actuated by the pressure in er:- traction conduit 54 bleeding steam from the intermediate section.

Over-How valve Qi is responsive top-ressure in the main conduit B and operates las the other overfiow valves herein before-explained.-

Both the speed regulator S in tron-t of the high pressure section and the speed regulator Sfbetween the high lpressure and intermediate pressure sections operate only when the 'number of revolutions of the turbine 'is higher than' normal value. The speed regulator X regulates the steam quantity tothe low pressure section of the turbine and'is in act-ive regulation at the normal number' of revolutions-of the turbine'.- y

, If'the high pressure section4 of the turbine and t'lielhigh pressure conduits wereomitted so that "the boilers delivered steam directly to conduit B1-the construction would be the saine as that vof'lFig'. 6. F or this reason it is unnecessary to go into a description of Fig.

- 8. It is only necessary to point out that va.-

`riations in conduits B are transferred to conduit B1, this being` accomplished by the operation ofvalves M, Q1 and'O. The regulating devices for plants having doublepeX--V traction; turbines can be arrangedas disclosed in connection with Figs. 6. and 7. It

is easily seen that sections T and U are ex@ actly analogous to sections T and U. in' these figures referred to.

To make the Aoperation ot the various regulating arrangements liereiir before. de-

scribed clear the description has been developed on the basis that each impulse, such as a pressure impulseor a speed impulseacts on a separate valve. The valves controlling the flow of steam to -t-he motor .are placedin series -in the steam'path of the motor. For example, in Fig. 6 there are three valves, Q,

Rand the valve controlled by speedgov-v ernor S in" series in the supply .conduit 55..

The reason that they can be placed in one conduit in series is that the operation, as will have been noticed by the preceding :description, is such that the valve which is most closedis .the controlling valve; that each separate impulse derived from any one of the governing conditions is able to shut off the steam through the niotor ora part thereo-and thus the desired result is obtained. The series connection is characterized by this condition that any impulse can decrease the How of steam through the power unit independently of the tendency of any of the other impulses to increase the lowt'herethrough.

However an arrangement involving several valves placed onev after the otheralways causes considerable drop in pressure in the medium passing through them; in this case steam. Hence it is often preferable to have the impulses act on asingle controlling member, which regulates the steam flow to the motor. Awherein this is accomplished. l

` Fig. 9, 3`represents a conduit through which steam Hows. This may be the supply conduit 55 of the previous figures. 2 is'the valve in the conduit which is to be con` trolled bya. plurality of impulses such as pressure and speed. 4 is a liquid pressure operated servo-motor, the piston 5 of which is connected by means of a stem with the valve membei-G. The lpressure liquid operating the servo-motor is controlled by slide valve '7 which operates to allow the pressure liquid to pass to and from the servo-motor in a mannershown bythe arrows. Slide valve 7 is connected toarin 11 by nieansof leverr 8 and rods 9 .and 1 0, The position of arm 11 controls the position ot slide valve7 and thus controlsthe supply of liquid to and return from the servo-motor. Arm 11 is are two pressure 'operated mechanisms. These inechanisnisrepresent in part the overflow andreducing valves ofthe previous figures.

Fig. v9 shows a. construction The pressures operate on the `two pistons 13 and 14 which are acted upon by springs 1'5 'and 16.v The spring 15 acts'on the .upper side of piston 13; spring 16 acts on the lower sde of piston 14.. The arrangement is such t -at the pressure impulse which closes the valve partly or entirely upon a riseofl pressure, namely the reducing impulse, operates the piston 14 while the pressure which opens the valve more or less upon a rise of pres'- sure, namely the over-flow impulse, operates .piston 13. If, for iiistance,.tlie arrangement should be applied to the plant shown in Fig.

3, the piston 14 and associatedparts corre-Ay spond to the actuating mechanism-for valve R and the piston'13 and associatedparts correspond to'tlieactuating mechanism for valve Q. The piston rods, 17 and 18 are hollow and in them are arranged slidable pins 19 and 20. Two springs 21 and 22 form re- Q5 and 2o one on-each side of the arm 1i arranged so that there 1s a certain amount otplay between the arm and the stops. The arrangement `operates in the following manner: i v

ll the pressure above the piston 14 for any reason rises, this piston with its rodlS is moved downwardlyand Aas the spring 22 is stronger than the spring 12 the arm 11 is also pressed downwardly as soon as the lost motion between'pin 20 and piston rod 18 is overeen-ie. 'l`hedownward movement of arm 1l causes slide valve 7 also to bev moved dowmvardly and the pressure fluid then cnA the servo-motor on the' upper side of piston 5 and the lower side of piston 5 is conne'itcd with `the out-tlow.v Thus the piston ii is moved downwardly and the main valve 2 'is closed more or less. The arrangement including the lever 8 operates to return slide 'alve T to its middle position'in well known manner.

Suppose on the contrary that the pressure aciinp on piston 1-t tails. This causes arm llto be moved upwardly by-aid of the spring 12,. provided no other im' mlse is acting to press the arm downwardly. Now it l he arm is moved luvwardly the slide valve 7 `will also move upwardly and the pressure liquid will pass'to the lower side of piston 5 in the servo-motor causii'ig the valve to open more or less.

Suppose the. pressure acting on piston 13 `should rise, this piston will then be moved upwardly compressing the spring and the arm 'll can be moved upwardly by the spring l2, provided no other impulse tends to move the arm downwardly. As explained,

thisl movement ot the arm will. cause the` valve to open. ll. on the other hand, the l'n'essure acting below piston 13 should drop, this pistonwill be moved downwardly by'. spring 15. ln this case, at first, the lost motion which ma)v occur between rod li' and pin li) will lie overiiome and then larm l1 will he movrd downwardly and the valve will l e clos-.ed` either partially or entirely.

il'. despite the action ofthe pressure regulators.- too much steam `flows through the conduit il.v thereby causing too much steam to pass to the motor, that the motor speeds up beyond its normal limit, the

speed regulator S will operate to move rod 2a down 11 downwardly and will cause the valve to decrease its llow arca thus decreasing the supply ot' steam therethrough. Consequently, in this case the speedregulator takes care of the regulation regardless of the eilect of the pressure operated elements. It', owing to the influence of a pressure impulse, too

`small a quantity of steam should be supplied tothe motor,the speed of the latter will decrease and when attaining the lowest permissible limit, the speed regulator will lagaincontrol thel regulation by causing the stop 96 to-bear against arm 11 which will increase the flow ol steam through the valve. lf, at this time, either ot the pressure impulses tends to shut the valve. the springs 4l or 22 will bei compressed and the effect of these impulses will be eliminated.

It is obvious that 1n place otl pistons 13 wardly whereby the stop Q5 will move arm I and 14 equivalent devices maybe used, such 4 as diaphragms or bellows.

It lwill be readily seen that it is not neces-` sary to insert a Yvalve il in the conduit sup plying steam to the motor if thc motor is .such that it is already provided with admission controlling valves arranged in the motor itself. In such `cases it is within the scope of this invention that the impulses be arranged to act on the existing governing devices of the motor.

'.llhat we claim. as new and desire to se cure by Letters Patent ot the United States olf America is 1. In a steam plant, in combination, a steam `generator. 'a motor, means to conduct steam from said generator to said motor, a low pressure conduit, an accumulator, an :ucuniulator conduit connected therewith, 4a

'reducing valve receiving steam` from 4said accumulator conduit and deliveringv the same to said low )'nessure conduit, means to conduct steam t'rom said generator parallel to said motorl to said accumulator, vmeans to conduct steam 'l'rom said motor to said low pressure conduit and a consumer connected to receive steam from said low pressure c0nduit. N

2. A sleamplant comprising in combination a steam generator, a steam motor, an vaccumulator, a consumer, means to'pass steam from said generator to said motor, meansto pass steam from said\ generator to said accumulator, a conduit adapted to lead steam `from said accumulator to said consumer, a member in said conduit responsive lo the pressure behind the same to control the How o'l steam therethrough, a connection between said-motor and said conduit, saidconnection being connected to said conduit at a point behind said member.

- 3. A steam plant comprising in combination a steam generator, a steam motor adapted to receive steam from said generator, a steam accumulator, a conduit leading steam from said generator toward said accumulal tor, means in said conduit responsive to the last-mentioned conduit responsive to the pressure-behind thea-same and operating to controlthe iiow of' steani therethrough, a connection adapted to receive steam from said motor and to deliver steam to said lastmentioned conduit at a point betweenv said memberl and said consumen 4. In a steam plant, in combination, a steam generator, a consumer, two parallel paths for thepassage, of steam from said generator to said consumer, the one ypath containing an over-flow valve and a reducing valve, and having an accumulator connected therewith between said over-flow valve and said reducing valve, and a steam motor in the' other path. y

5. Ina steam plant, the combination with a source of steam, a motor and an accumulator supplied from said source, a consumer Supplied both from the motor and the accumulator of automatic means to control tiowL of steam from the accumulator to the consumer responsive to variations oi' pressure in the steam supplied from the' motor.

6. A steam plant comprising in combination a steam generator, a steam conduit system connected therewith, asteam motor in Said conduitsystem, an accumulator in said conduit system, a consumer inl said conduit system, a connectionl delivering steam from said motor toward saidconsumer, means to maintainv a lower pressure in said connection A connection leading steam from the motor leads steam into said last mentioned conduitl than in said accumulator, and means to con trol the steam flow to said motor responsive .to the pressure in 'front of said 'motor and responsive to the pressurein said connection.

7. A steam plant comprising in 'combination a steam generator, a lsteam conduit system connected therewith, an extraction `motor, an accumulator and a steam consumer in said conduit system,vmeans to withdraw steam from said motor and supply the same to said consumer,` means to supply steam from said accumulator to said consumer; means to maintain the extraction pressure always lower than the pressure in said ac.

cumulator, means operative atvtlie normal speed of the motor to control the steam iiowY tov said motor responsive to variations of pressurein steam supplied to said motor and variations of pressure in steam withdrawn rom'said motor, and means responsive to the speed of the motor operating at a value `oi speed somewhat higher than thenormal speed of the motor to nullify the eifectot the pressure'responsive means, and to control theliow of steam to said motor.

8. In a steam plant, in combination, a steam generator, a consumer, two parallel paths for How of 'steam 'from said generator toward said consumer, the one path containing an over-low valve and a reducing valve, and having an accumulator connected therewith between said over-flow valve and said reducing valve, means to convert the Venergy of steam intokinetic energy in the votherpath and mechanism to regulate said means responsive to they pressurel before and behindvsaid means.

9.'A steam-plant as set out in claim 6 wherein the means to control the flow of' steam to the motor, besides being responsive to pressure, also includes mechanism responsive tothe speed of the motor.

l0. A steam plant comprising' in combination a'stcam generator, a steam moto!l adapte-dto receive steam 'from said generator, a steam accumulator, a conduit leading steam 'from said'generator toward said accumulator, means in said conduit responsive to the pressure in front of the sanie to control the How 'ot steam through said conduit toward said,accumulator and adapted to allow flow of steam uponanincrease of said pressure above a. predetermined value, a supply conduitleading steam. to said motor and a connection leading steam from said motor, means to control the steam How to said motor responsiveto .the pressure in said supply conduit and the pressure in said connection, aconsumer, a. conduit connecting said accumulator with said consumer, a member in said last mentioned conduit'responsive toA the pressure behind the same and operating to control the iowof steam therethrough, and meanswherebjv the said at a point between said ineinber and said consumer;A

1l. In a steam plant, inl combination, a steam generator, a consumer, two parallel paths for passage of steam from said generator toward said. consumer, the. one path containing an over-How valve and a reducing valve and having an accumulator connected therewith between said over-flow valve and said reducing valve, means to steam generator, a high pressure conduit connected therewith, a conduit of lower said conduit of lower pressure, a valvepressure, a lconnecting conduit for passage ol' steam trom said high pressure conduit to in i said connecting conduit responsive to ,the pressure in frontof` the same and operating to` increase its flow opening upon an increase of the actuating' pressure and decreaseits How opening upon a decrease of the actuating pressure, an accumulator .connected with said conduit or" lower 'pressure and adapted to receive steam` passing through said connecting conduit,

reducing valve in said conduit .of lower pressure, a, motor adaptedto receive steam from said4 high pressure conduit, apconnection lea( ing steam from said motor to saidl conduit oi lower pressure at a point behind said reducing valve, means to control the steam flow to said motor responsive to the pressure in front thereof, responsive to the pressure in said connection and responsive to the speed of the motor and a steam consumcrconnected to 'said conduit ot lower' pressure at a point behind said reducing valve.

13. A steam plant as set out in claim 6 wherein the meansto control the steam liow to the motor comprises a plurality of mechanisms arranged ahead ot said steam motor, one ot lwhich mechanisms is responsive 4to the pressure of steam supplied'to the motor and another otsaid mechanisms to the pressure ot steam in the connection delivering' steam from the motor toward the consumer.

111. In a steam plant, in combinatiom'a steam generator, a high pressure conduit, anacci'unulator, an' accumulator cor-.duit connected therewith, a connecting conduit for passage of steam from said high pressure l conduit to said accumulator conduit, a valve in said connecting conduit responsive to the pressure in tront'ot the same and operating to increase the iiow otl steam therethrough when said pressure increases and to decrease vthe flow 'of Isteam therethrough when the pressure decreases, a low pressure conduit, a consumer connected with` said low pressure conduit, and adapted to receive steam therefrom, means to pass steam from the accumulator conduit to the low pressure conduit operated by the pressure in the low pressure conduit, a motor. composed of several sections 'including a high pressure sec-- tion, a supply conduit connecting said high pressure' conduit with said high pressure section tosupply `steam thereto. connection leading steam 'from said high pressurel section to said low pressure conduit and means to control the flow ot steam to said high pressure section.

15. In a steam plant, in combination. a

conduit to said accumulator condnit,a valve steam therefrom, means to pass steam 'from' the accumulator conduit to the low pressure conduit operated by the pressure inthe low pressureconduit, a motor composed of 'several sections including a'high pressure section, a supply conduit connecting said high pressure conduit with said high pressure section to supply steam thereto, a connection leading steam from said high pressure sectionto saidlow pressure conduit and means to control the' flow of steam through4 said high pressure section responsive to the pressure in said supply conduit and responsive to the pressure in said connection.

16. In a steam plant, in combination, a steam generator, aliigh pressure conduit, an accumulator, 'an accumulator. conduit connected therewith, a connecting conduit for passage of steam from said high pressure conduit to said accumulator conduit, a valve in -said connecting conduit responsiveto the pressure in front of 'the same and operating to increase the flow ot steam therethrough when said pressure increases and to decrease the tlo'w of steam therethrough when thepressure decreases, a low pressure conduit, a consumer connected with said low press ire conduit and adapted to receive steam therefrom, means to pass steam `from the accumulator conduit-to the low pressure conduit opconduit, a motor composed of several sections including a hioh pressure section anda low pressure section, a supply conduit connecting said high pressure conduit with said high pressure section, a connection ,leading steam from said high pressure section to said low pressure conduit, a steam comn'iunication between saidhigh and lowl pressure sections, speed responsive means to control the flow of steam through said:communication and pressureiesponsive means to control the iiow of. steam through said high pressure section. l

17. In a steam plant, in combination, a steam generator, a high pressure conduit, an accumulator, an accumulator conduit connecte-dtherewith, a connecting conduit for passage of steam from said high pressure` conduit to said accumulator conduit,- a valve in said connecting conduit responsive to 'the pressure in front .of the same and operating' to increase-the flow of lsteam therethrough when said pressure increasesand to decrease`\ the iiow of steam' therethrough when the pressure decreases, a low pressure conduit,

a,consunier connected with said low pressure conduit and adapted to 4receive steanitherefrom, means to pass steam from the accumulator conduit to the. loW pressure conduit operated by the-pressure in the low pressiii/e conduit, a motor composed of several sections including ahigh pressure'section and a low pressure section, a supply conduit connecting said high pressure conduit with said high pressure section,'a connectionleads 'ing steam from said high pressure section to said low pressure conduit, a `steam comaccumulator, an accumulator conduit c'onnected therewith, a connecting conduit for the passage of steam from said high pressure conduit to said accumulator conduit, a valve in said connecting conduit responsive to the pressure in front ot' the same and operating to increase the How of steam there-` through when said pressure'mcreases and to decrease fthe flow ot steam therethrough when the pressure decreases,.a low pressure conduit, a consumer connected with said low pressure conduit and adapted to receive' steam therefrom, means to pass steam from the accumulator conduit tothe low pressure conduit operated by the pressure in the pressure conduit, a motor composed of several sections including a low pressure sectioinineans to control the steam passing to said low pressure section, a connection leading from said motor at a point ahead ot vthe last mentioned incans to said low pressure conduit and means to control the slipply of steam to said motor.

lfljlii a steamv plant, in combinatioma steam generator, a high pressure conduit, an zuzcuinulator, an accumulator conduit connected therewith, a connecting conduit for passage of'steam from said high pressure conduit to said accumulator conduit, a valve in said connecting conduit responsive to the pressure in rontiof the same and operating .to increase the fiow of steam therethrough when said pressure .increases and to decrease the flow of steam therethrough when thepressure decreases, a lowpressure conduit,

a consumer connected with said low pressure conduit and adapted to receive steam therefrom, means to pass steam froinvthe accumulator conduit to the low 'pressure conduit operated by the pressure in the low pressure conduit, a motor composed of several sec 'tions including a loiv pressure section, a

. motor responsiverto the pressure in said sup'- ply conduit and in said connection.

20. In `a steam plant, in combination, a

steam generator, a high pressure conduit 'connected therewith and adapted to receive steam therefrom, aconsumer connected to said high pressure conduit, an accumulator, an accumi'ilator conduit connected therewith, a connecting conduit for passage'ot steam from saidhigl'i pressure conduit vto said accuinulator conduit, a valve in said connecting conduit responsive to the pressure in front of the same and adapted to allow How of steam therethrough when said pressure rises above a predetermined value, a low pressure conduit, a consumer connected to said' low pressure conduit and adapted to receive steam therefrom, means topass steam from the .accumulator conduit tothe low pressure .conduit operated bv the pressure iii the low pressure conduit, a motor including a low pressure section and assection of higher pressure, a supply conduit connecting said high pressure conduit with 'said motor to supply steam thereto, a steam coinnu-inication leading steam from said section of higher pressure to said loW pressure section, a valve in said communication, a

speed responsive device to control said valveoperating during normal speed of the motor,

a connection leading from a point in said communication ahead of said\valve to said lowv pressure conduit, means responsive to the pressure in said connection to control the 'flow otsteam through said section of higher pressure and other means to control the flow 'of steam through said section of higher prestherewith, a reducingvalve receiving steam from said accumulator conduit and deliverinfi the san'ieto said low pressure conduit,

means to conduct steam from said generator parallel to said consumer to said accumulator, means to conduct steam from said consumer to said low pressure conduit and a second consumer connected to said low pressure conduit. i

4Q2. ln a steam plant, in combination, a steam generator, a condensing extraction consumer, means to conduct steam from said generator to said consumer, a low pressure conduit, un accumulator, an accumulator conduit connected therewith. a reducing valve receiving steam from said accumulator conduit and delivering,r the same to said low pressure conduit`r means to conduct steam from said generator parallel to Said -condensing extraction consumer to said accumulator, means to extract steam from said condensing' extraction consumer and deliver the same to said 10W pressure conduit, and a consumer' connected to said 10W pressure conduit.

NILS PERSSN.

JoHANNEs sums. 

